Gasoline fuel compositions



April 18, 1961 A. c. NIXON ETAL GASOLINE FUEL COMPOSITIONS Filed Dec.16, 1955 6 u M .0 m H O I; III I J IOO%A COMPOSITION OF INHIBITOR WINVENTORS ALAN C. NIXON HARRY B. MINOR THEIR ATTORNEY United StatesPatent'O 2,980,519 GASOLINE FUEL COMPOSITIONS Alan C. Nixon, Berkeley,and Harry B. Minor, Orinda, I Calif., assignors to Shell Oil Company, acorporation of Delaware I a Filed Dec. 16, 1955, Ser. No. 553,629 L 6Claims. (Cl. 445-09) This-invention relatesto organic compositionsstabilized against oxidative;deterioration. The compound2,6-ditertiarybutyl-4-methylphenol is used extensively, to inhibit theoxidative deterioration of yario usorganicsubstances, particularly oils,fats, waxes and-the 'like,'which are normally. subject to oxidativedeterioration. About 5 to 5 /2 million pounds ofthis 1 to achieve thedesired oxidation inhibition of'the organc material for economic reasonsand also tominimize the possibility of undesirable side effects. It isalso desirable,

- of-course,'to achieve as high a resistance to oxidation as possible'atany given concentration of inhibitor. Y Y .It' is an object of thepresent invention to provide'improved organic compositions, containingan especially eifective oxidation inhibitor. Another object is toprovide such compositions-satisfactorily inhibited against oxidative.decomposition with a particularly small concen- .tration of an oxidationinhibitor. Another object of the invention is to increase theeffectiveness of 2,6-ditertiarybutyl-4 methylphenol as anaoxidationinhibitor for organic substances. Other objects of the invention will beapparent from the description of the invention.

It has now been discovered that mixtures of2,6-ditertiary-butyl-4-methylphenol and 2-tertiarybutyl-4-methylphenolexhibit synergistic interaction in the inhibition of oxidativedeterioration of organic material, the combination being more effectivefor this purpose than either compound alone, the maximum efiectivenessbeing between about 50 and 70%, and usually about 60%, by weight of2,6-ditertiarybutyl-4-methylphenol. This efiect is illustrated in thedrawing in which the single figure is a graph of theoxidation-inhibiting effectiveness of mixtures of2,6-ditertiarybutyl-4-methylphenol and Z-tertiarybutyl- 4-methylphenol,these compounds being represented in the drawing as A and B,respectively.

The data of the drawing were obtained from tests conducted in thefollowing manner:

The organic material used as a base was a typical commercial premiumgasoline containing no added oxidation inhibitor and having thefollowing composition and properties:

gi meme, VOL 43 corporated, the severity of the conditions to which the'g'jli 07 65 material is to be subjected, and the length of time the80440 Straight run gasoline 305 material must be protected againstoxrdative deterioracrzson F. thermal and cat cracked gaso tion. Forexample, in gasoline, jet fuel and other hydroline "percen't vol" 303carbon distillates. the lower concentrations are ordinarily 250-430 F.hydrogenated cat. cracked gasoh that p to about 045% y Weight, and lipercent 1 26,7 70 preferably from about 0.000] to about 0.02% by weight.

Cat. reformed gasoline do 7.5 On the other hand, in transformer oils,turbine oils and Tetraethyl lead (motor mix) cc./U.S. gal-.. 2.74

Hydrocarbon Type Analysis:

Saturates percent vol-.. 60 Olefins 19 Aromatics rln 21 5 Properties: V

Gravity API-.. 56.4 1 Reid vapor pressure lbs 8.3

ASTM distillation, F.:

I.B.P. 98 10% evaporated 134 50% 223 90% a 379 F.B.P.' I 418 Totalsulfur percentwt" 0.15 Research'octane No. 94.5

To this base gasoline was'added 2,6-ditertiarybutyl-4-r methylphenol and2-tertiarybutyl 4-methylphenol individually and in mixtures of varyingproportions, with the total concentration of these twocompounds beingheld constant at 10 milligrams per 100 milliliters of gasoline.Induction periods of the resulting gasoline solutions wereobtainedunde'r 100 p.s.i.g. oxygen pressure at 100 0., following theprocedure prescribed in ASTM method No. D-525-49. The results arepresented in Table I, as well as in the drawing, the compound2,6-ditertiarybutyl- 4-methylphenolbeing designated as A, and thecompound- Z-tertiarybutyl-4-methylphenol being designated as B: V

Table I I Increase in Induction Induction Proportions of InhibitorMixture, Percent wt. Period, Period V Hours Otieir Base,

. ours ers naptha, paint solvents, and the like, lubricating oilsespecially such as turbine and transformer oils, paraffin,

microcrystalline and tank bottom waxes, polyethylene waxes, and residualoils such as bright stock, residual fuel oils and asphalts, as well asto rubber, food products and animal, vegetable and fish derived oils,fats and 6 waxes. Particularly beneficial results are generally achievedin the case of liquid hydrocarbon products and I especially hydrocarbondistillates.

The benefits of the combination inhibitor of the invention may beobtained over wide ranges of total concentration. The totalconcentration may be as low as .0.00005% by weight to as high as 1.5% byweight depending upon the particular material in which it is inotherheavy hydrocarbon liquids and hydrocarbon solids,

higher concentrations will often be advantageous, that is, above about005% by weightand preferably from about 0.1 to 1.0% by weight.

The proportions of the two components of the combination inhibitor ofthe ini/en'tion can bevari ed extensively, material benefits beingobtained 'when the mixture contains substantial proportions of ""ciichJAs can be 'seen from an inspection of the dr'awi'rig, theinixture in allproportions exhibits the combination effect thatthe effectiveness isgreater over the entire Trange than would be calculated byarithmeticproportion of the effectiveness of the individual components.However, it is preferred that at least about 15% by W'e'ight 2i 6ditertiarybutyl4-methyl'phenol be present so at'the e'lfectiveness ofthe mixture ise'ven gr'eate'r th'tnlliat;"of"this component alone, andingerie'fal, it is also preferred that at least 5%, and mereespeciany atleast by weight 2-tertiarybutyl-4-methylphenol be 'piisen't; fit is,Qpreferable that at'leas't 20% "and more especially "at least 25 byweight 2,6-ditertiarybutyl-4-methylphenol be present in the mixture.Thus, with the preferred minimum of by weight2,6-ditertiarybutyl-4=methylphenol and the preferred minimum of 5% byW'eigbtZ-tertiarybutyl-4-methylphenol, the proportion range ofth emixture is from 15 to 95% by weight 2;6'-"ditertiarybutyl-4 methylphenoland from 85 to 5% by WeightZ-tertiarybutyl-4-methylpheno1. Similarly,with the especially referred minimum of 25% byweight2,6-diteftiarybutyl- 4-methyl and the especiallypreferredniinimuin' of 10% by weight Z-ter tiarybutyl-4-rnethylphenol,the proportion range of the mixture is from 25 to 90% by weight 2,6-ditertiarybutyl-4-methylphenol and from 75 to 10% by weight2-tertiarybutyl-4-rnethylphenol.

We claim as our invention:

1. A gasoline fuel consisting essentially of gasoline and containing asmall amount, sufficient to stabilize said fuel against oxidativedeterioration, of a mixture consisting of from about 25% to about 75% byweight it equal parts by weight of 2,6-ditertiarybutyll-methylphenol andZ-tertiarybutyl 4-methylphenol.

3. A gasoline fuel consisting essentially of gasoline containingtetraethyl lead and from about 0.00005 to about 1.5% by weight of anoxidation inhibitor consisting essentially of a mixture oi "from about25 to about 90% by weight of 2,6-ditertiarybutyl-4-methylphenol and fromabout 75 to about 10% by weight ofQ-tertiarybutyl-4-methylphenol.

- 4. A gasoline fuel consisting essentially of gasoline containingtetraethyl lead and from about 0.0001 to about 0.15% by weight of anoxidation inhibitor consisting essentially of "from about 25 to about90% by weight of 2,6-ditertiarybutyl4-methylphenol *and from about 75 toabout 10% by weight of 2-tertiarybutyl-4-methylpha 5. A gasoline fuel"consistingfe'sse'rltially of gasoline containing tetraethyl lead andfrom about 0.0001 to about 0.02% by "weight 1? 'of as oxidation"inhibitor {consistingess'entially of a mixture of from about 25 to"about90% by weight of 2.6 'cliteftiarybutyl fimethylphefiol and from about75tolab'out 10%bytqiight of Z-tertiarybutyI- 4- lmethylphenol.

6. A gasoline fu'ebconsisting essentially of gasoline containingtetraethyl leadand from about 0.0001 to about 0.02% by weight ofanoxidation inhibitor consisting essentially of a 'mixture 'of 26-ditertiarybutyl-4rnethyl phenol and 2-tertiarybutyl 4-methylphenoLQthe concerttration of 2,Q-ditertiarybutyl-4}methylpheriol in saidmixture being from about to byweight.

Bennettei ning in the file b: this patent} UNITED STATES PATENTS".2,202,s77 Stevenset al.- 2.; Junta-Q1946 2,459,597 Still'sonet al. Jan.18.1949 2;672;448- Newman et a1. Mar. 16,1954

2,721,804 Rosenwald .*..Oct. 25,1955

I {bitten EFERENCES Food Manufacture, October 1954; page 398. i

Alkyl Phenolsas' Antioxidants," by Ros'efiwald, Heatson, and Chenicek,Ind. and Eng. Chem January 1950,

yol. 42. No. DQ111863 1 2 65.

3. A GASOLINE FUEL CONSISTING ESSENTIALLY OF GASOLINE CONTAINING TETRAETHYL LEAD AND FROM ABOUT 0.00005 TO ABOUT 1.5% BY WEIGHT OF AN OXIDATION INHIBITOR CONSISTING ESSENTIALLY OF A MIXTURE OF FROM ABOUT 25 TO ABOUT 90% BY WEIGHT OF 2,6-DITERTIARYBUTYL-4-METHYLPHENOL AND FROM ABOUT 75 TO ABOUT 10% BY WEIGHT OF 2-TERTIARYBUTYL-4-METHYLPHENOL. 